^^84 Mr Hardy on the Geology of the 



edges. They are traversed by numerous thin laminae of white 

 quartz. The limestone has a tendency to acquire, on exposure, 

 a blackish colour ; and its weathered surface exhibits the quartz 

 laminae protruding in numerous plates, giving rise to a sort of 

 honeycombed or reticulated appearance. The quartz laminae 

 sometimes alternate with layers of the darker-coloured limestone 

 — thus exhibiting a structure somewhat analogous to that of 

 gneiss. When a portion of this rock is plunged in dilute nitric 

 acid, it dissolves slowly with effervescence, the quartz laminae 

 are left unchanged, or slightly corroded on the surface, while 

 the silica which was in combination with the earthy carbonates 

 is precipitated in the form of a fine powder. Carbonate of 

 magnesia is associated in considerable proportion with the car- 

 bonate of lime, but the rock does not afford a lime capable of 

 forming a mortar. Iron and manganese may be detected by 

 the usual reagents in its composition *. 



Associated with and passing into the above occurs a rock of 

 a coarser angulo-granular texture, composed of quartz and fel- 

 spar, the latter either the common or the glassy variety. This 

 rock is internally of a greyish colour, its weathered surface be- 

 ing of a rusty brown. Mica in minute scales is of rare occur- 

 rence, and rhomboidal crystals of calcareous spar are also occa- 

 sionally present. This rock passes into a quartz similar to that 

 described as occurring in the ranges to the south ; and, as the 

 strata of the latter are in the direct line of bearing of those 

 which now occupy our attention, and as both preserve the same 

 relative position to the argillaceous schists by which they are 

 flanked, we may perhaps conclude that they form but modifica- 

 tions of the same rock considered geologically. In other posi- 

 tions I have observed differences equally great in the internal 

 texture and composition of strata which seem to form one con- 



• During the very imperfect analysis which my limited means enabled me 

 at the time to institute, some rather anomalous results, depending on metal- 

 lic combinations, were obtained. I could not, however, depend on the purity 

 of the reagents which I possessed ; and as I had no opportunity of procuring 

 others, and no means of preparing them, I mention the circumstance in this 

 passing way, in the hope that some other observer, whose duties may lead 

 him to that quarter, will undertake the analysis. The hill where the rock 

 occurs will be at once distinguished by a small Hindoo temple erected on its 

 summit. 



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